It is a current trend that future vehicles will be connected. Connectivity provides new means for both safety and convenience applications as well as autonomous driving. Connectivity between vehicles can be realized both through direct communication between vehicles and between vehicles and roadside infrastructure, e.g., using automotive Wireless Fidelity (WiFi) according to the IEEE 802.11p standard, also referred to as Intelligent Transportation System operating in the 5 GHz frequency band (ITS G5), and also through communication over an existing mobile cell network. Communication in this way may e.g., be via some cloud-based back-end system.
A challenge related to cloud-based communication between vehicles or between vehicles and infrastructure is that many communication messages may need to be routed from the cloud to specific vehicles, often based on the location of the vehicle, i.e. using unicast of messages rather than broadcast of messages.
Previously known solutions to manage distribution of information to vehicles based on the locations of the vehicles have proposed a pattern where the same subset of data, relevant to an area or to a position within the area, is sent to all vehicles within that area. This may be done through applying a grid pattern that defines areas in which the same information is broadcast to all vehicles therein. In this case, the actual communication implementation could be unicast, i.e. cloud-to-one-vehicle, but since the same data is communicated to all vehicles in the area, it is in practice a broadcast. This previously known solution is a relatively rough method since vehicles will receive a fair amount of irrelevant data, including data related to roads that the vehicle is unlikely to travel. This might be relevant e.g., in cases where there are no interconnections between local roads next to a highway road although the roads are close to each other in the same geographical area.
A prerequisite for a unicast solution to work is that a message routing logic in the cloud must have access to the current position of all connected vehicles, in order to be able to route information only to those vehicles in the road network to which the information in the message is relevant. This prerequisite requires the connected vehicles to report their present position to the cloud with some interval. The position reporting will have to be frequent enough in order to keep the location of the vehicle up-to-date and will constitute a significant part of the overall data traffic occurring for these types of cloud based applications. Despite the data traffic incurred by a required update of the current position of each connected vehicle, this type of unicast solution is still motivated since an alternative broadcast solution where all messages are transmitted out to all vehicles is estimated to result in an significantly higher usage of bandwidth to each vehicle.
However, there is still room for improvements relating to this type of cloud based unicast communication solutions.